Trouble converting old Lima Class 33 to DCC

Post all your DCC only problems, solutions and discoverys here.
jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Trouble converting old Lima Class 33 to DCC

Postby jonzo » Tue Feb 27, 2018 1:34 pm

Hi folks

I'm new to DCC and have recently built a small layout which is controlled by a Hornby Select. I picked up the Somerset Belle train set as it was a bargain and that came with an 0-6-0 loco and other bits and pieces, although the layout is built from older track.

The 0-6-0 runs perfectly (after a good clean of the track), so I've started to convert my other locos. First up is my old Lima Class 33, bought around 25 years ago so definitely not modern internals.

I picked up an 8-pin DCC loom off eBay, which is roughly 6" long and wired that to the loco. I've then plugged in a Lenz Digital Plus decoder.

When first placed on the track the motor judders a bit and then it stops after a few seconds. The loco doesn't initially respond to DCC (as ID 3), however I noticed (by accident) that when the 0-6-0 was on the same bit of track that both locos started running. I removed the 0-6-0 and the 33 kept running until stopped.

I've tried programming the 33 to ID 1 but it didn't seem to want to have any of it, and doesn't respond.

This isn't giving me a lot of confidence in DCC, but I'm hoping to get to the bottom of the problem. I could flog the locos and buy DCC, but I won't have learnt anything from that so would like to understand the issues.

Is my DCC loom too long, there is probably a foot of cable in total coiled inside the loco as I didn't want to cut the plug off the decoder? Is the problem with the Lima pancake? The wheels on the loco have been scrubbed up with a track rubber and seem okay, but I gather DCC is really sensitive.

Thanks in advance for your help

jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Re: Trouble converting old Lima Class 33 to DCC

Postby jonzo » Tue Feb 27, 2018 1:55 pm

And just to add, the 33 ran okay on DC recently.

User avatar
Mountain
Posts: 2898
Joined: Mon Oct 24, 2016 3:43 pm
Location: Somewhere in Wales, UK.

Re: Trouble converting old Lima Class 33 to DCC

Postby Mountain » Tue Feb 27, 2018 2:13 pm

Were you able to isolate the dc wires between the wheels and the motor (Both contacts) before soldering the decoder wires to the loco?
The basic wiring for a decoder... (Remember this rhyme!) ...
Red and black → To the track!
Orange and grey → The other way. (To the motor).

I've wired a few class 33's (Lima) and have not had any issues. I hope all is sorted.
Enjoying 7mm narrow gauge.

jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Re: Trouble converting old Lima Class 33 to DCC

Postby jonzo » Tue Feb 27, 2018 2:19 pm

Yeah I removed the two wires from the front of the 'pancake' then soldered the red and black to the contacts the DC wires were on. And the orange and grey to the brush retainers as before.

I followed this http://mrdccu.com/_Media/nem652-nmra-8- ... g_med.jpeg pinout which I think has the same colours as you've mentioned.

Are your 33's still running the pancake motors?

Bigmet
Posts: 6203
Joined: Tue Aug 14, 2007 2:19 pm

Re: Trouble converting old Lima Class 33 to DCC

Postby Bigmet » Tue Feb 27, 2018 2:36 pm

If you cannot reprogramme the address that's usually a sign of something wrong in the wiring that needs to be checked out. DCC requires good track supply to work well, and Lima isn't ideal in this respect. The greasy brass used for the wheels quickly oxidises, and there are traction tyres which dirt up the track and prevent the powered wheels being used for pick up. It's all bad news. The guys keen on Lima tend to put Ultracale wheelsets in them, you end up paying as much as for a modern high grade centre motor mechanism!

Personally, I believe you will learn more about DCC's potentiality by buying a current design of diesel with a centre motor drive from Bachmann or Heljan, and see just what it can deliver. I've attached an example of what can be got new at giveaway price, prepare to be blown away if you try it.

http://www.hattons.co.uk/62751/Heljan_2 ... etail.aspx

jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Re: Trouble converting old Lima Class 33 to DCC

Postby jonzo » Tue Feb 27, 2018 3:15 pm

I'll look into the pickups, but I was able to meter out the same voltage on the black and red at the DCC socket as I was getting at the rails (circa 8 volts AC).

I have a Lima Class 60 open ready for conversion, that's newer and has not had a lot of running. That was going to be next, but I might tackle an old Hornby Class 25 on which I have a new CD motor to install (the Ringfield is knackered).

RFS
Posts: 860
Joined: Tue Jan 12, 2010 3:09 pm
Location: Derbyshire, UK

Re: Trouble converting old Lima Class 33 to DCC

Postby RFS » Tue Feb 27, 2018 4:43 pm

Just wondered whether your problem is the Hornby Select. It's a very basic DCC system and is not NMRA-compliant in some aspects, and some makes of decoder are known to have problems with it.
Robert Smith

Bramshot
Posts: 192
Joined: Thu Jul 07, 2016 6:55 pm

Re: Trouble converting old Lima Class 33 to DCC

Postby Bramshot » Tue Feb 27, 2018 6:13 pm

8 volts is surely a bit low for dcc. Should be 14 V or more, as measured on ac range multimeter, so as dcc is squarewave will not be an accurate measurement, but 14V should be about right.

User avatar
RAFHAAA96
Posts: 488
Joined: Tue Feb 19, 2008 1:39 pm
Location: Cyprus

Re: Trouble converting old Lima Class 33 to DCC

Postby RAFHAAA96 » Tue Feb 27, 2018 6:19 pm

Even though you disconnected the wires from the motor brushes you still need to confirm with a meter that there is no continuity between either brush and thenwheels as some motors have one brush live to the chassis and hence to the wheels on one side.

If your Select runs the ‘Belle’ loco then it will run a Lenz decoder just as easily. I just do not get this constant Select bashing. It is a basic controller and no worse than similar starter level units from other manufacturers and in some case it is better.

When programming the new address in, do make sure that is the only loco on track.
Rob
RAF Halton Brat - 96th Entry
http://www.halton96th.co.uk

jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Re: Trouble converting old Lima Class 33 to DCC

Postby jonzo » Tue Feb 27, 2018 6:35 pm

Yeah I was a bit puzzled by the track voltage but assumed it wasn't metering correctly.

The Select appears to have software version 1.5, and I believe NMRA compliance is now stated?

I'll look for any concealed pickups on the 33 as that would indeed seem the most logical conclusion to the judder.

Was also thinking of wiring the CD motor to another loom and then connect the red and black to the track directly (croc clips) just to check that the decoder isn't an issue before overhauling the old (circa 1983 and it was secondhand then) Class 25.

Mike Parkes
Posts: 529
Joined: Sat Sep 01, 2007 8:25 pm

Re: Trouble converting old Lima Class 33 to DCC

Postby Mike Parkes » Tue Feb 27, 2018 7:43 pm

Problem could be a fault in the 8 pin loom (a badly soldered wire onto the socket for example) - where locos do not have a dcc socket its simpler just to hard wire a decoder in place, and less likely for faults to appear provided you heatshrink any joints (but then you should do that anyway with any wires connected to the loom). The good news is Lenz decoders are pretty robust and if their is a wiring fault the decoder may still be okay. If you were to hardwire the Lenz the grey and orange wires from the decoder can be soldered direct to the motor contacts.

jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Re: Trouble converting old Lima Class 33 to DCC

Postby jonzo » Tue Feb 27, 2018 8:10 pm

I've tried another loom, with red and black direct to the track and orange and grey direct to the CD motor. I get the same result with the Lenz attached - Pulsing and will not respond to DCC.

I've checked the 33 over and there are no shorts, all wired as it should be, checked plug polarity etc. Track is reading nearer 14v, I think my meter may need a new battery..

The same thing as before happens with the 33, though. Place the 0-6-0 on the track next to it (same loco ID) and they both respond to the controller. I assume the Hornby decoder is doing the handshaking and the Lenz also picks up the signals from the controller.

Not sure what is going on, but these V2 + Lenz decoders don't seem to be compatible with the select. Tempted to pick up a Hornby decoder to see what happens.

Bigmet
Posts: 6203
Joined: Tue Aug 14, 2007 2:19 pm

Re: Trouble converting old Lima Class 33 to DCC

Postby Bigmet » Wed Feb 28, 2018 8:36 am

jonzo wrote:...Not sure what is going on, but these V2 + Lenz decoders don't seem to be compatible with the select.

Ah, you have a 'Select'. Sorry to tell you this but it is the Select that is well known as not fully DCC compatible. Well documented from the time of its launch that its output is not compliant with the DCC signal specification.

Best advice, no Hornby DCC kit, controllers or decoders. The DCC specialist makers gear is infinitely preferable.

jonzo
Posts: 13
Joined: Tue Feb 27, 2018 11:57 am

Re: Trouble converting old Lima Class 33 to DCC

Postby jonzo » Wed Feb 28, 2018 10:03 am

Yeah this thread on the Hornby forum seems to tell a similar story to mine https://www.hornby.com/uk-en/forum/sele ... -firmware/

Apologies if cross-links are not allowed here.

User avatar
End2end
Posts: 3771
Joined: Sun Jan 12, 2014 9:58 pm
Location: At the end....... and sometimes at the other end

Re: Trouble converting old Lima Class 33 to DCC

Postby End2end » Wed Feb 28, 2018 10:55 am

RAFHAAA96 wrote:It is a basic controller and no worse than similar starter level units from other manufacturers and in some case it is better.

I have to disagree. My Bachmann Starter controller never has these COMMON Hornby problems. OK so it can only run 9 DCC'd locos. But at least it CAN run them.
Plus I have never heard of any constant problem with my controller like we hear over and over and over again with Hornby Selects.
As a side note I have TCS and LENZ decoders and NONE have any problems with my controller.

Back to the subject in hand, have you tried perhaps going up just one number say by changing from 3 to number 4 instead of a longer or higher address?
Thanks
End2end
"St Blazey's" - The progress and predicaments.
Welcome‎
Planning
Building
St. Blazey's Works & Depot thread


Return to “DCC Forum”

Who is online

Users browsing this forum: No registered users and 4 guests